If you copied this script, press Ctrl+V to paste it into Scripter. If you downloaded it, click File | Open, select the BAS file from your downloads directory, and click Open.

Click Script | Run to run the script.

*********

'DataThin.bas reads the data file and writes every nth point to a new file.
Sub Main
Debug.Print "----- ";Time;" -----"
file1 = GetFilePath(,"dat;txt;xyz",,"Open Data File")
n = InputBox("Read every n-th data point","Enter 'n'","2")
file2 = Left(file1,Len(file1)-4)+"_Thinned_"+n+".dat"
Open file1 For Input As #1
Open file2 For Output As #2
linenum = 0
While Not EOF(1)
For i = 1 To n
Line Input #1,a
Next i
Print #2,a
Wend
Debug.Print file2+" has been created."
MsgBox(file2+" has been created.")
End Sub